The SLC6A20 gene helps move certain amino acids, especially proline, in the kidneys and small intestine. If it does not work well, your body may lose more of these building blocks in urine, which can contribute to a condition called iminoglycinuria and is often mild. This gene became better known during the COVID-19 pandemic, when researchers studied it because it works closely with ACE2, a protein involved in coronavirus entry into cells.
What is a gene?
Genes are stretches of DNA that carry instructions your cells use to make molecules or manage activities in the body. Some genes provide the directions for producing proteins, the parts of cells that do much of the work. Others mainly help regulate when certain processes happen, where they take place, and how strongly they run. Together, genes affect how the body develops and functions, and they can also shape how you respond to food, stress, or medications. More information on this topic is available in the LearnHub.
Overview
SLC6A20Gene function
What if the gene works
The SLC6A20 gene helps cells take up proline and similar building blocks.
It is most active in the intestine and kidneys, where it supports normal nutrient handling.
Risk
What if the gene does not work
Variants in the SLC6A20 gene can reduce kidney reabsorption of glycine and imino acids, causing excess amounts in urine, called hyperglycinuria or iminoglycinuria. Effects can range from mild to more marked, and many people have few or no symptoms.
Treatment
What does that mean for your treatment
No SLC6A20-specific treatment or drug selection approach is currently established in clinical guidelines for people with a pathogenic or loss-of-function variant in the SLC6A20 gene. The SLC6A20 gene is being studied in early research on amino acid transport, kidney stone risk, and ACE2-related pathways, but this has not led to gene-directed treatment choices.
Conditions associated with SLC6A20
Gene function
What if the gene works
Your body needs a steady supply of protein building blocks to support normal cell work. The SLC6A20 gene helps move one of these building blocks, called proline, across cell membranes. It is most active in the small intestine and kidneys, where it supports amino acid transport and helps the body use and conserve nutrients.
The SLC6A20 gene makes a transporter protein that moves proline and a few similar amino acids into cells. It uses the natural movement of sodium and chloride to carry these nutrients across the cell surface.
In the small intestine, this transporter helps absorb proline from digested food into the cells lining the gut. That supports amino acid transport in the small intestine and helps your body make use of nutrients from meals.
In the kidneys, it helps take proline back from forming urine into kidney cells. This reuptake helps your body conserve useful amino acids instead of losing them in the urine.
What is a variant?
A genetic variant is a slight change in the DNA sequence of a gene. These changes are common and are part of normal human diversity, including differences in appearance, metabolism, and the way the body responds to environmental influences. Many variants do not have any noticeable effect and simply represent natural genetic variation. In some cases, though, a variant can change how a gene works more substantially and may contribute to or cause a genetic condition.
Genetic variants
What if the gene does not work
Variants in the SLC6A20 gene can alter the transporter protein’s shape, stability, or ability to reach the cell surface, which may reduce amino acid transport across the membrane. Milder variants may leave some activity, while more severe variants can produce a very unstable protein or no working protein at all. This spectrum helps explain how SLC6A20 gene variants affect protein function and, in some cases, the degree of amino acid transport change seen on testing.
How variants are linked to conditions
At this stage, variants in the SLC6A20 gene are not yet tied to a broadly confirmed, specific health condition, though this may become clearer as research develops. If you have a confirmed change in the SLC6A20 gene, your doctor or genetic counselor can place that result in the context of your own health and family history.
A variant is not necessarily a diagnosis
Variants in genes are a usual part of human biology and are common throughout the general population. Most do not directly affect health and instead reflect natural human diversity. For many genes, having a variant associated with a condition suggests a possible link rather than a confirmed diagnosis, especially when several genes and environmental influences play a role. In some situations, though, a single well-characterized variant in a specific gene is enough to confirm a diagnosis.
Are there things that can increase or change my risk?
There is not yet broadly confirmed evidence on specific factors that clearly increase or reduce health risk related to the SLC6A20 gene. If you have a change in SLC6A20 on genetic testing, a doctor or genetic counselor can help explain what it may mean in the context of your own health and family history.
Inheritance of SLC6A20 variants
There is not yet a broadly confirmed single disease inheritance pattern for the SLC6A20 gene, because the conditions linked to this gene are uncommon and inheritance may vary depending on the specific variant and clinical picture. In practice, discussions of how SLC6A20 gene variants are inherited are usually cautious rather than absolute. The SLC6A20 gene is located on chromosome 3, which is an autosome, so you inherit one copy from each parent. That means a variant in this gene can be passed down through either side of the family.
What does my SLC6A20 result mean for my family?
There isn't yet a broadly confirmed inheritance pattern tied to a specific condition for SLC6A20, though this understanding can change as research develops. If you have a specific SLC6A20 result and questions about what it could mean for your family, a doctor or genetic counselor can explain it in the context of your result and family history.
Genetic information
Genetic testing
How you find out about variants
To find out about variants in the SLC6A20 gene, SLC6A20 genetic testing uses DNA from a blood sample, saliva, or a cheek swab. A laboratory reads the gene’s sequence and compares it with the usual reference pattern, then reports whether a variant was found and how clearly its health meaning is understood.
When should I consider getting a genetic test?
There is not yet a broadly established reason to order SLC6A20 testing on its own. It may be considered as part of a broader genetic workup if there are unusual urine test results involving certain protein building blocks or a family history of a related inherited kidney condition.
A genetic result is only one part of your health story
Genetic test findings can be informative, but how much they reveal varies depending on the condition and the specific type of variant. Over time, many other factors also shape how the body functions, including lifestyle, environment, age, and medical history. For some conditions, especially those influenced by many genes, genetic information offers context rather than certainty and is best considered alongside other parts of care. In other situations, a genetic result can provide a clear answer. In areas such as response to medication, genetic results may also help put personal experiences into context.
Pharmacogenetics
How variants shape your response to medicine
Genetic variation can affect how your body handles certain medicines, including how they are absorbed, broken down, or moved through the body. That helps explain why the same medication may work well for one person, cause more side effects in another, or seem to have less effect for someone else. These differences are common and are one part of why treatment response varies alongside age, liver and kidney function, other medicines, and overall health.
What is Pharmacogenetics?
Pharmacogenetics is the area of study that examines how genetic differences affect the way people respond to medications. It looks at the relationship between genes and drugs to better explain why the same treatment may work differently from one person to another. For many medicines, genes help shape how strongly a drug works or how the body handles it. This understanding can support more informed, individualized treatment decisions. More detailed information on this topic is available in the LearnHub.
Drugs influenced by the SLC6A20 gene
When should I seek medical advice?
There is not yet a broadly confirmed role for this gene in guiding medication choices or predicting medication response. Questions about medicines, side effects, or changes in how a treatment is working are best discussed with your doctor.
History
The SLC6A20 gene entered the medical literature through studies of inherited amino acid handling in the kidney and intestine, especially in families with iminoglycinuria, a condition that affects how certain amino acids appear in urine. Initially understood only through visible traits, later recognized as tied to a specific gene, this work helped connect older biochemical findings to modern genetics. From these first observations, research expanded steadily. In the 2000s, scientists mapped and described the gene in more detail as part of a broader effort to catalog transport genes involved in digestion and kidney reabsorption. Public recognition grew much later, when large COVID-19 genetic studies highlighted a region containing the SLC6A20 gene. That attention brought this previously little known gene into wider research discussions.